Lubricating grease compositions



United States Patent LUBRHQATING GREASE COWOSI'IIONS Raymond L. Mayhew,Summit, N.J., and Joseph P. Copes,

Easton, Pa, assignors to General Aniline & Film Corporation, New York,N.Y., a corporation of Delaware No Drawing. Filed Mar. 21, 1961, Ser.No. 97,128 4 Claims. (Cl. 25251.5)

The present invention relates to improved lubricating greasecompositions, and relates more particularly to thickening agents forlubricating grease compositions.

This application is a continuation-in-part of our applications SerialNo. 625,234, filed November 30, 1956, and Serial No. 822,999, filed June26, 1959, both now abandoned.

Lubricating greases are generally made by forming a homogeneoussuspension of soap in non-volatile and viscous lubricating oils. Informing the greases, the soaps, generally fatty acid soaps of earthmetals, such as, calcium, soda, aluminum, barium, lead, lithium, etc.,are usually made in contact with the lubricating oil with agitation atelevated temperatures. When the incorporation of the soap and theviscous oil is finished, the product is cooled at a definite rate andthen milled to impart desired viscosity characteristics. When sodiumgreases are heated and cooled, they tend to set to a very heavy masswhich are unstable to shearing forces. The calcium greases on the otherhand have low dropping points. Both the calcium and sodium greases havelittle rust preventive action and the Water resistance of the sodiumgreases is quite low. In contact with water, such greases tend toemulsify and wash away, thus losing their effectiveness as a lubricant.

Therefore, an object of the present invention is to provide alubricating grease composition having therein a thickeneing agent withwhich said lubricating composition is rust inhibiting, water resistantand stable to shearing forces. I

Other objects and advantages of the invention will become more clearlyapparent from the following description.

The above and other objects of the present invention are accomplished byadding to any petroleum hydrocarbon such as petroleum oils, petrolatum,mineral oils, having a Saybolt viscosity at 100 F. of 50* to 5,000, athickening amount of at least one N-substituted-w-hydroxycarboxylic acidamide characterized by the following general formula:

OH R dH-CHBCH2C ONHO wherein R represents either hydrogen or a methylgroup, R represents an organic radical, devoid of water solubilizinggroups such as sulfonic or carboxylic acid groups, containing from to 30carbon atoms, e.g. decyl, undecyl, undecylenyl, hendecyl, dodecyl,tridecyl, tetradecyl, cetyl, myristolenyl, pentadecyl, heptadecyl,hexadecyl, hexade cenyl, octadecyl, octadecenyl, octadecadienyl,abietinyl, dehydroabietinyl, dihydroabietinyl, oleyl, elaidyl, erucyl,monylbenzyl, octylbenzyl, diamylbenzyl, dioctylbenzyl, etc., andmixtures of such radicals, and R represents either hydrogen or an alkylgroup of from 1 to 18 carbon atoms, e.g. methyl, propyl, butyl, amyl,hexyl, nonyl, decyl, dodecyl, cetyl, ootadecyl, etc., the total numberof carbon atoms constituting the groups in both R and R being a minimumof 10 and not more than 48 carbon atoms.

The compounds utilized in accordance with the present invention areobtained by the reaction of one mole of an aliphatic N-primary amine ormixtures of such amines containing from 10 to 40 carbon atoms with onemole of 3,325,530 Patented Mar. 17, 1964 either 'y-butyrolactone or'y-valerolaotone at a temperature of -95 C. as disclosed in applicationSerial No. 625,224, filed November 30, 1956, and now abandoned, thecomplete disclosure of which is incorporated herein by reference to thevarious compounds per se which are useful as thixotropic and thickeningagents and to the method of preparing the same.

As illustrative examples of the thix-otropic and thickening agentscharacterized by the foregoing formula, the following may be mentioned:

(1) The reaction product of N-decylamine and 'y-'bu tyrolactone.

(2) The reaction product of N-decylamine and 'y-v-alerolactone.

(3) The reaction product of N-dodecylamine and 'y-blltyrolactone.

(4) The reaction product of N-cetylamine and v-butyrol-actone.

(5) The reaction product of octadecylamine and 'y-butyrol-actone.

(6) The reaction product of 1 mole (86.1 grams) of v-butyrolactone with1 mole (274 grams) of a commercially available mix-ture of amines havingthe following composition: hexadecylamine 10%, octadecylamine 10%,octadecenylamine 35%, octadecadienylamine 45%.

(7) The reaction product of 1 mole (86.1 grams) of 'y-butyrolactone and1 mole (365 grams) of a commercially available mixture of amines(derived from tall oil) and having the following composition:octadecenylamine 15%, octadecadienylamine 15 abietylamine 70%.

(8) The reaction product of 1 mole (86.1 grams) of 'y-butyrolactone and1 mole (276 grams) of a commercially available mixture of amines havingthe following composition: hexadecylamine 6%, octadecylamine 93%,octadecenylamine 1%.

(9) The reaction product of 1 mole (86.1 grams) of 'y-butyrolactone and1 mole (317 grams) of a commercially available primary amine made from amodified rosin '(dehydroabietylarnine) having the following formula:

(10) The reaction product of 1 mole (100.1 grams) of y-valerolactone and1 mole (365 grams) of a commen cially available mixture of amines havingthe following composition: ootadecenylamine 15%, octadecadienylamine15%, abietylamine 70%.

(11) The reaction product of 0.2 mole (7.2 grams) y-butyrolactone with0.2 mole (58.9 grams) of the monoamide prepared from coconut oil andethylenediamine in the usual manner.

(12) The reaction product of 1 mole (86.1 grams) -butyrolactone with 0.2mole (65.3 grams) of stearamidoethyl amine.

(13) The reaction product of 0.5 mole (43 grams) 'y-butyrolactone with0.48 mole (320 grams) of polymerized fatty acid derived amine. The acidis available on the market under the brand name of Empol 1022 and isessentially a C dibasic acid resulting from the polymerization ofnaturally occurring unsaturated C fatty acids. The general properties ofthe polymerized acid (from which the amine is derived) are as follows:

(14) The reaction product of 1 mole of 'y-butyrolactone with 1 mole of acommercially available mixture of amines having the followingcomposition: octylamine 8%, decyl amine 9%, dodecyl amine 47%,tetradecylamine 18%, hexadecyl amine 8%, octadecyl and octadecenyl 5%.

The thickening agents of the present invention as previously stated areemployed in any petroleum hydrocarbon currently utilized in thepreparation of various types of greases. The nature or character of thelubricating oil or mineral oil is immaterial so long as it has aviscosity of 50 to 5,000 at 100 F. (S.S.U.) (secs. Saybolt Universal).The greases are in the form of gels and when theN-substituted-'y-hydroxycarboxylic acid amides, when present in theproportion of 0.1% to 3% by weight of the petroleum hydrocarbon ormineral oil, form smooth semi-solid masses at room temperature. Theamount of the thickening agent to be employed may range from 0.1 to ashigh as 10% based on the weight of the petroleum hydrocarbon and mayvary somewhat depending upon the type of petroleum oil used. In mostinstances, an amount ranging between 0.1 to 2% is sufiicient to impartgelling characteristics. The exact gelling mechanism has not yet beenclearly established. It is believed, however, to be related to thehydrogen bonding character of the various N-alkyl- -hydroxycarboxylicacid amides.

In preparing the grease compositions of the present invention, theN-substituted-v-hydroxycarboxylic acid amide is added to the petroleumhydrocarbon having the foregoing viscosity characteristics in theaforementioned amount, and the mixture heated to a temperature between60 and 120 C. and the mixture then cooled to room temperature. As thetemperature is lowered, a point is reached below which a stablethixotropic gel is obtained. Gels can also be prepared by mixing thepetroleum hydrocarbon with the thickening agent and maintaining thesystem below the temperature at which the low viscosity solutionobtains. In this case, the gelling agent with the passage of time gelsthe petroleum hydrocarbon. The gels and greases can also be obtainedwhen the system, i.e., mixture is maintained at constant temperature andthe gelling agent first dissolved and then gelled.

The greases or gels of the present invention have the advantage of beingthixotropic stiif gels before working, and are rust inhibiting, thusprotecting the metal on which they are used. They are water resistant,and hence do not tend to emulsify and wash away. In addition, they formfilms which greatly improve lubrication since such films are not subjectto shearing forces as compared with ordinary greases and lubricantswhich operate upon their viscosity eifects alone. The greases of thepresent invention reduce friction in the higher pressure system, and donot deposit any undesirable residues. They burn without forming ash.

In order to disclose the invention in greater detail, the followingexamples are furnished. It is to be clearly understood that theseexamples are merely illustrative only and are not intended to limit thescope of the invention claimed. All parts given are percent by weight.

Example 1 Percent The product of illustration (1) 2 150/100 F. (S.S.U.)(seconds Saybolt Universal),

asphalt base red oil 98 The product of illustration (1) and the oil wereheated together to C. to effect solution. The molten mass allowed tocool with slow agitation until it formed a smooth semi-solid mass. Themass was then allowed to cool to room temperature and agitated slowlyuntil it became smooth, and of clear appearance. The penetrationstability was determined according to the ASTMD 217-47T (Amer. Soc. forTesting Materials, Specification D-21747). The resulting grease had adropping point estimated at 78 C.

Example 2 Example 1 was repeated with the exception that the product ofillustration (1) was replaced by products of illustrations (6), (7) and(8). The percent employed of the latter and the results obtained are asfollows:

Dropping Product of Illustration Percent Point Estimated, C.

Example 3 Viscosity Viscosity (Ccntipoiscs) 2% of Gclling Gclling Agent2% of Gclling Agent in Light Agent in Lubri- Mineral Oil eating OilCompound of Illustration:

(l 900 750 970 735 1, 200 800 2, 350 1,200 970 800 (8) 1,300 Blank(untreated oil-viscosity) 540 15. 5

In some lubricating grease compositions, the rust inhibiting propertiesare enhanced by heating one mole of an N-substituted-y-hydroxycarboxylicacid amide with one mole of diethanol amine, triethanol amine, etc. forone hour at 150 C. with stirring and then allowing the mixture to coolat room temperature. The resulting product is readily compounded withvarious types of liquid petroleum hydrocarbon by merely mixing andheating to a temperature slightly under which the liquid petroleumhydrocarbon will thicken to oil. The mixture is thereafter stirred toinsure homogeneity and allowed to cool. In general, the rust inhibitingproperties of the oil compositions prepared in accordance with thepresent invention are so good that the addition product with diethanolamine, etc. is not necessary.

Example 4 The compound of illustration (6) was treated withdiethanolamine to form an addition product and then compounded withkerosene at a concentration of 0.1%, warmed slightly and cooled. Thiscomposition was noted to exist as a pronounced gel.

Example The compounds of illustration (8) were compounded with keroseneat a concentration of 0.1%, warmed slightly and then cooled.Subsequently, a pronounced gel was formed.

The thickening agents of the present invention are capable of producingvarious types of greases. The exact nature of the grease will bedictated by the application to which it is to be applied. The nature ofthe grease will also depend considerably on the hydrocarbon liquid whichis gelled, the exact thickening agent used, the proportions of eachconstituent of the composition and the technique of the manufacturewhich involves the manner of incorporating the thickening agent, thedegree of heating employed, the rate of cooling the composition afterheating and the physical stress and shear to which the composition issubjected during and after the cooling operation.

Thus, greases of any desirable consistency may be produced, for exampleNational Lubricating Grease Institute grades 1 through 6 by merelyvarying the compo sition. By way of illustration, an oil of 540 cps. at25 0, initial boiling point of 375 C., containing about 5% of theproduct of illustration (14) will have an ASTM (D2l752T) penetration ofapproximately 2%.

The compounds of the various illustrations when employed as thickeningagents have, in certain cases, exhibited antioxidant properties. This isa very desirable property in a lubricant additive.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing from the spirit of this invention.

What is desired to be secured by Letters Patent is:

1. A grease composition comprising (a) a liquid petroleum hydrocarbonhaving a Saybolt viscosity at about 100 F. in the range of from about 50to about 5,000, and (b) a thickening agent in an amount in the range offrom about 0.1 to about 10 percent by weight of said petroleumhydrocarbon, said thickening agent consisting essentially of thereaction product of an alkanolamine and at least oneN-substituted-y-hydroxycarboxylic acid amide having the followinggeneral formula:

OH R-(il' H-C HzCHzC ONHCE wherein R represents a member selected fromthe class consisting of hydrogen and methyl group, R represents anorganic radical containing from 10 to 30 carbon atoms, and R representsa member selected from the class consisting of hydrogen and an alkylgroup of from 1 to 18 carbon atoms, the total number of carbon atomsconstituting the groups in both R and R being at least 10 and not morethan 48 carbon atoms, said reaction product being formed by reactingequimolar amounts of said alkanolamine and said amide at about 150 C.for a period of about 1 hour.

2. A grease composition according to claim 1 in which the alkanolamineis diethanolamine.

3. A grease composition according to claim 1 in which the alkanolamineis triethanolamine.

4. A grease composition comprising (a) a liquid petroleum hydrocarbonhaving a Saybolt viscosity at about F. in the range of from about 50 toabout 5,000, and (b) a thickening agent in an amount in the range offrom about 0.1 to about 10 percent by weight of said petroleumhydrocarbon, said thickening agent consisting essentially of thereaction product from the reaction of diethanolamine with the amideproduct formed from 'y-butyrolactone and a mixture of amines consistingof 10% hexadecylamine, 10% of octadecylamine, 35% of octadecenylamineand 45% of octadecadienylamine, said reaction product being formed byreacting equimolar amounts of said diethanolamine and said amide productat about C. for a period of about 1 hour.

References Cited in the file of this patent UNITED STATES PATENTS2,898,301 Mayhew et al Aug. 4, 1959 2,923,738 Williams et al. Feb. 2,1960 2,958,665 Stefcik et al. Nov. 1, 1960

1. A GREASE COMPOSITION COMPRISING (A) A LIQUID PETROLEUM HYDROCARBONHAVING A SAYBOLT VISCOSITY AT ABOUT 100*F. IN THE RANGE OF FROM ABOUT 50TO ABOUT 5,000, AND (B) A THICKENING AGENT IN AN AMOUNT IN THE RANGE OFFROM ABOUT 0.1 TO ABOUT 10 PERCENT BY WEIGHT OF SAID PETROLEUMHYDROCARBON, SAID THICKENING AGENT CONSISTING ESSENTIALLY OF THEREACTION PRODUCT OF AN ALKANOLAMINE AND AT LEAST ONE(-SUBSTITUTED-$-HYDROXYCARBOXYLIC ACID AMIDE HAVING THE FOLLOWINGGENERAL FORMULA: